How to play the brain

Method 1: middle finger on top of the thumb, the middle finger is ready to go, other fingers naturally forward, lock the target, quickly release the thumb, quickly strike.

Method 2: the index finger follows the example of the middle finger in method 1, the middle finger is still maintained, but do not force, lock the target, with the largest joint of the index finger and the middle finger backhand knocking the target door of the head.

Method three: knocking on the door will not?